Recently, a composite material (FRP) made of plastic and reinforced fiber attracts attention as a high-strength light-weight material, and various fan rotor blades utilizing such a composite material are developed (see Patent Documents 1 to 4 listed below).
In a fan rotor blade utilizing the above-mentioned composite material, its blade body is constructed of the composite material. For example, the blade body is constructed of a composite material composed of thermosetting plastic such as epoxy resin or thermosoftening plastic such as polyetheretherketone (PEEK) and reinforced fiber such as carbon fiber. In addition, the blade body has a suction-side surface (convex surface) and a pressure-side surface (concave surface).
A blade root is integrally formed at a base end of a blade body. The blade root is also constructed of the composite material composed of thermosetting plastic such as epoxy resin or thermosoftening plastic such as polyetheretherketone and reinforced fiber such as carbon fiber. In addition, the blade root is coupled with a joint slot formed on an outer circumference of a fan disc.
Along a leading edge of the blade body, a sheath for protecting the leading edge is provided. The sheath extends along a span direction, and is composed of metal. Further, along a trailing edge (or, along an end edge and a trailing edge) of the blade body, a guard for reinforcing the blade body may be provided. Similarly to the sheath, the guard is composed of metal.